E30 superlite

[rix313]

Fuel tank arrived. Modify it, mount it.

4,2 kg saved, left/right weight distribution improved.



Leak tested and underside painted with epoxy:

I had been thinking about this but didn't have a spare to hack into and see what happened to so speak! Do You have any more pictures of the tank during modification etc? Any idea what the capacity of the tank is?

[Jarno]

I had been thinking about this but didn't have a spare to hack into and see what happened to so speak! Do You have any more pictures of the tank during modification etc? Any idea what the capacity of the tank is?

Neither did I, so I bought a new one and cut it to pieces to see what happens.

No pics of the work, as it was a quick job.
The breather pipes that run on the upper face can be pretty much twisted off by hand. Then just cut it in half, and beat it straight where your weld seam is going to be. I tacked it to place, then gave it to our garage's resident master of TIG-welding. Slapped an extra layer of epoxy paint on the underside to protect it from rocks, sand.. you know.
And ofcourse the connecting pipe place needs to be shut. Bolt to the hole, weld.

I made a muffler. I plan to have only one, and off-the-shelf ones that fit, are straight thru type "silencers". Now I don't want to have exhaust sounding like 1500hp if the engine has 150.

Single inlet, expands to 4x56mm pipes that change to 4x60mm pipes. Then, through 4X30 holes to a small chamber then single exit. All of the four pipes have plates that make the sound waves bounce/change direction.
Packed with random "exhaust wool"
I call it a "chambered semi-straight through" muffler



Located just in front of the fuel tank. I'll have to come up with some clever heat shields I think.

[rix313]

Was there an opening across the top that needed welding shut then? That is what I had thought. If it needs welding then for sure wouldn't mess about trying to weld up a used one. New ones are pretty expensive in the UK though. I have a motorsport ATL 30L fuel cell I could fit though

[Jarno]

Was there an opening across the top that needed welding shut then? That is what I had thought. If it needs welding then for sure wouldn't mess about trying to weld up a used one. New ones are pretty expensive in the UK though. I have a motorsport ATL 30L fuel cell I could fit though

Yes there are a couple of openings. Hammering, vise grips and cursing solved that. I did it, so it can't be difficult or expensive . I paid 180€ for the tank, not sure who's product it is, not OEM anyway. Check Ebay.

Welding any used tank is a bad idea. Filling it up with water, ventilating, etc.. none of it removes the fumes so there's always risk of it going BOOM big time.

I stuck with original type tank because all parts surrounding it can remain stock, plus it's in the lowest possible point, weight within the wheelbase in the corner that I want. Not so with one the box shaped race tanks that people put in trunks. Thought of having any fuel system part inside the chassis gives me the chills. Even a well designed system will fail, given enough time and mileage. Better it leaks outside if it's going to.

Didn't answer your question. I'm guessing it holds 30-35 liters. But I can drive the tank to fumes on track because I have a scavenging system.

[rix313]

Haha. With regards to putting the tank in the boot I agree with you there. The standard tank location is spot on. In all fairness by the time a 'custom' or after market tank like the one I have has been made to fit and appropriate modifications made for the wiring and plumbing etc, a replacement OEM tank could be bought and be far less fuss.

This short video from the Kumho BMW championship sums up why I also wouldn't put the fuel tank in the boot:

[youtube][/youtube]

[Jarno]

I disassembled the rear arms:




Angle grinder, wire brush, sand blasting, acid..

-still work in progress.
edit.... :





Back together with new parts..

[Jarno]

I bought a pair of Recaros.. They need new linings but that's a small problem. Only one of them in the pic. The other is torn gray

Short video of the seat, how it works. Commentary is in elvish: http://petrolhead.kuvat.fi/kuvat/BMW+31 ... 220403.3gp


Rear axle, done!

[Jarno]

[Jarno]

..I realized that the pipes for parking brake cables need to be modified . Well that's not a big problem I hope.

[Jarno]

E36 (M-sport?) control arms with eccentric M3 bushes and new joints. Bushes move the wheel 2cm forwards, and the arms move it about 4-5mm. In all, quite a bit. Change in caster angle and caster trail should be noticeable. I even calculated how much it affects weight distribution , by ~1% or so.



Sway bar links will be M3-style for all the obvious reasons:

[martinpallot]

Those are just ordinary e30 arms - e36 arms have rubber bushed ball joints and e36 m3 Evo arms have the outer ball joints which aren't set back.

[Jarno]

Actually they are not E30 arms. Came from an E36, distinguishable by that rubber abomination you mentioned, and the outer joint hole is bigger than on E30.
I laid these, dismantled, on top of similar E30 arms, and the ball centerline is 4-5mm further front. I replaced the joints with Meyle HD items. They're without the rubber, and joint "outer race" is metal not plastic like on OEM.

[Jarno]

Spent three nights investigating what kind bump steer I get with my front end setup. I actually got some useful results and I was able to make it more neutral . Now I believeI can fine tune it and I know how to change it if the need arises in the future.

Jarno

[Jarno]

Back from a holiday.
Started clawing and grinding rust off of the front struts..





Oh and I've been fighting to replace the heater core to a friend's E30, plus we were testing another friend's racer at Avenisto circuit:
We're all beginners at track testing but managed to get some useful data. I think

[Jarno]

I realized that my front dampers actually are knob adjustable, not push-till-it-bottoms&twist-type. Which was nice.


I want to be sure that the top spherical bearing doesn't make the steering sticky even with peak wheel load, so a thrust bearing is in order I think:



Front subframe epoxie'd


-required a bit of welding before paint


Bought a set of 11,8:1 comp Wössners

1 complete piston with everything, is 212 grams lighter than stock.


If anyone's interested in the OEM 89,96mm pistons I have, PM me.
Unused, comp. height 42,5mm with 4,4mm dome. 10:1 CR with an M10 121TI head. Can be used with E30 head also. Comes with rings, pins, pin locks. Going cheap.

finally got around to building a railing and stairs to my 2nd floor junk storage. There are 2 qualified electricians in our garage but lighting is still undone

[Jarno]

Bored out to 90m, deck straightened. I told them to only get it straight, not to shave off ANY extra, which they did.
Pistons are a bit too high even now so shaving extra would make matters more difficult.






Trying my new tool on a scrap block that I got for 20€, bought it because I need a set of E30 type rods and an oil pump.


Machinist shop GAVE me this, which was nice :


DIY heat shielding for DIY muffler

Last missin bits of the front suspension.

Brakes, brake lines DONE except for rear right pipe.

..I was happy to notice that the front sway bar drop link mod A) works at all and doesn't collide with stuff and B) works just like I imagined it would. I set the drop link mounting points so that when you have steering angle, one side will push and the other link will pull a bit. So in straight line it works like a thin sway bar it is, but during cornering it has pre load even without actual roll.

update..
I was able to move the fuel tank a bit rearwards. Still tight fit with the muffler. Crossing my ingers that it won't heat the uel too much..


I'll line the tank forward egde with this:

2,80€ from the grocery store

Standing on all four:

[Jarno]

Steering joint angles don't look too bad.

-and nevermind tthe awkward brake pipe routing.. I was tired and ran out of ideas.




I've got a pile of engine parts on order plus Megasquirt, wide band lambda, sensors etc. Pictures when I get them.
Anyone interested in buying a kidney from me?

[Jarno]

316i radiator isn't big but should be adequate with everything else properly done


Cooling fan mountings sort of done + radiator "tunnels" have extra sealing.


Megasquirt and wideband lambda stuff arrived. Still waiting for a bunch of parts.

[Jarno]

I assembled the pistons and installed to block. A bit tricky to measure how much the top land is over deck height, since almost the whole piston top is domed.

So, I found TDC with a dial indicator, then just put a feeler gauge next to piston like in the pic and try with another feeler which is higher. Accurate enough? My measurements varied from "bit over ,85mm" to "a bit under ,95mm" over the block. Feel free to comment/advice, this is new territory to me !



Anyway.. If I assume that pistons are 0,95mm over block (to be on the safe side), and buy a 0,066" head gasket, that would give 0,72mm piston to head clearance.

Measuring how deep the valve pockets are in relation to deck height @ TDC felt a bit tricky too. Anyway they are lower than deck height. With 2,6mm TDC lift the valves shouldn't collide. I need to verify this but hopefully no piston grinding is needed.

Friend told me he's halfway through soldering the engine management box.. New black roof lining or whatdoyoucall the roof upholstery in under work. It'll be without any of the rear seat belt etc. holes.

edit.. some parts arrived

[rix313]

Cooling fan mountings sort of done + radiator "tunnels" have extra sealing.

You shouldn't need this shroud with an electric fan dude. It's the front one that will help you out, this won't do anything for you.

Top stuff going on

[Jarno]

Well actually it does, just like it would with on original type fan. The fan sucks air from radiator rear surface, but the air chooses the path of least resistance. With out a sealed "tunnel" meaninful amount of air that the fan displaces,would be sucked in from the sides. This way, all fan displaced air must travel throuh radiator fins.

That fan is actually quite efficient despite it's dimensions. It's weight with mountings is what troubles me :/
Lightening a car on a shoestring budget is tedious work.

Stock 89mm E30 piston compared to a 90mm Wössner


And thanks for the kind words.

[rix313]

It's the air going into the radiator you need to channel. The reason there is a shroud with the standard fan is because it is away from the radiator. Without the shroud it would just throw are around the engine bay. Your electric fan is mounted directly to the radiator. Up to you but it is pointless with your set up.

[Jarno]

I will be using the front shroud too, with a rubber seal around the edges.

Some more stuff bought:




-The old crankshaft rear seal had eaten a groove in to the crank. Nothing too big. It looked like the new seal's lip is a bit deeper toward the engine. Also I'll be assembling that seal "frame" with sealing compound instead of an OEM paper gasket, that also moves the crank to seal contact point away from the groove.

I dropped the cylinder head off to a guy who has a CNC-machine at his garage, he'll grind the combustion chamber edges. Like I might have mentioned, I haven't even tried to calculate or measure the CR. Piston maker quotes 11,8:1 but that depends on what head is the starting point for grinding, head height, block height, gasket thickness etc.. My guess is prettydamnhigh :1. My cam is quite aggressive, so with it, the dynamic CR probably won't be too high.

[Jarno]

Crank back from maching shop. Just polished, no other stuff done. Here's hoping that the journals haven't gone thinner. I measured the clearances and bought the bearings BEFORE I realized the crank had scrathes.. Possibly scratched by the same mystery shit that had scraped a mark to no. IV piston skirt. I've used assembly oil generously, kept everything clean and left parts protected from dust etc. when I finish. But my garage isn't exactly a laboratory.



A 0,066" thick Cometic head gasket with 91mm holes should be on it's way. Well, I'm anticipating a long delivery time but anyway. The nice people from Cometic told when I asked them, that the catalog-gasket with 90mm holes might be a bit too close for 89,93mm piston that is 0,9mm above deck. Managed to change my order.

Surprising difficulty with the pistons/ head work. The machinist told me the combustion chamber cant be opened enough for the piston domes, he'd hit the valve seats. First solution that came to mind would be to machine the domes a bit narrower, then copy the shape to combustion chambers.

[Jarno]

Two of the crank journal clearances were ~0,02mm too big. Just happened to find these on Ebay , just the amount I need!

(As everyone probably knows, ) OEM "blue" bearings are 0,01mm tighter per part


Now all clearances are ~0,05mm. Factory spec is 0,03-0,07mm


I got the ECU back. Started fiddling with the wiring harness etc. Not much else to do, still waiting for stuff for engine assembly.

I'm trying to do a proper job of the wiring. Replacing wire from end to end and not doing extensions/unneccessary connections etc. Just cutting the old wires and re connecting them would be a lot less work but that method has many potential problems.













NOS crank rear end flange seals.. Probably older than me



New OEM conrod wrist pin bushes, timingchain cover seals, crank seal (pulley side), valve stem seals.



Luckily, that crank needle bearing fits the crank (6 bolt 1966 M10 crank) and the 262 CR Getrag's "clutch axle". Wasn't quite sure about that, browsing the parts catalogue. Ofcourse the correct installing depth is a bit of a question mark.


-that plastic tube is for installin stem seals, I guess?

[Jarno]

On with my monologue.. No word from many engine parts I've ordered. I did finish (pretty much)mating car electrics to the engine wiring harness. Except, when the time comes I'll have to cut everything, shorten as needed and reassemble with couple of 10 or 14 pin sockets. Difficult to explain what I'm getting at here. :/

A "somewhat lighter than stock" battery:

Huge weight saving by using shock bolt as ground point (& deleting the original)

VIDEOCLIP http://petrolhead.kuvat.fi/kuvat/1984BM ... system.mp4 , testing how the small radiator fan moves air. Very well! - don't know if the clip illustrates it well but..

[Jarno]

Copper coated aluminium cable, lighter stuff than the original


ITB adapter "still work in progress"


A bit of a side project.. A friend had an ix diff in his 318iS and asked me to swap a 4,27 ratio to it.. Well this should be interesting if even doable..

[initial_g]

Youve done some work.. however im thinking just fitting a grp or carbon boot, bonnet wings and doors would have saved so so much more weight also a alloy fuel cell would have saved over standard. A grp bonnet over a steel bonnet is 18kg a grp bonnet is 2.3kg thats a massive saving without messing with cutting lugs off here and there, im intregued thats all as mines been on a diet and ive gone about it differently

[Speedtouch]

I would have been tempted to drill the rear subframe/wishbones also for some added lightening (as are the front wishbones as standard, i.e., with holes along their length), but bearing in mind, of course, that they are structurally important parts taking quite a considerable strain, so perfectly understandable to leave them as standard.

[Jarno]

Youve done some work.. however im thinking just fitting a grp or carbon boot, bonnet wings and doors would have saved so so much more weight also a alloy fuel cell would have saved over standard. A grp bonnet over a steel bonnet is 18kg a grp bonnet is 2.3kg thats a massive saving without messing with cutting lugs off here and there, im intregued thats all as mines been on a diet and ive gone about it differently

Ofcourse, budget allowing, I'd have valves and conrods made from unobtainium to save weight. Fact is, right now I'm very bugdet restricted. It may be till my kids move out of the house before I can afford carbonfiber -anything-. Won't let that get me down, this car changes owners only upon my death so I have time I can improve on it/rebuild/develop every winter. But you make a good point about the bonnet, that thing is fukking heavy!

Anyway.. Every part that goes into the car, I consider just "evo1". If I had the dough, I'd go and buy for example 15x7" wheels that still weigh less than the 14x6"s I have now. And some day I will.
About the fuel tank. Just about everyone is fitting race tanks to their E30's. However I don't need one (no race regulations to meet), and the standard tank is in optimum position. As low as possible and just within the wheel base. Not so with a fuel cell in the boot. 4,2kgs was dropped by cutting the tank in half. Plus I hate the idea of having any fuel system parts inside the body. Smallest leak + a spark or me dropping my Marlboro.. scares me.

I would have been tempted to drill the rear subframe/wishbones also for some added lightening (as are the front wishbones as standard, i.e., with holes along their length), but bearing in mind, of course, that they are structurally important parts taking quite a considerable strain, so perfectly understandable to leave them as standard.

Front arms are cast steel, rear ones are pressed/welded sheet metal. Their structure is completely different, cannot be compared. Rear trailing arms are stiff like a soda can. Mess with the structure and they're gone. And let us not confuse stiffness and strength ;).

-Jarno

[initial_g]

[Jarno]

Like I said, some day budget will improve and so will the car.
I'm not limiting myself to big/expensive weight losses, rather trying to comprehensively rebuild the car with weight in mind. With every part that goes back in, I ask 1) do I need this at all, 2) can I afford a tiny bit lighter part or fabricate one, 3) can I lose some weight from this existing part and/or or it's mountings?

Drilling holes and cutting useless bits off is cheap and it all adds up ! !

[Jarno]

......

Surprising difficulty with the pistons/ head work. The machinist told me the combustion chamber cant be opened enough for the piston domes, he'd hit the valve seats. First solution that came to mind would be to machine the domes a bit narrower, then copy the shape to combustion chambers.

..aand that's what we did. Got my stuff back, finally:



Step two of thee side project. Sandlast the diff cover til you run out of sand, then wipe some acid to it, leave it waiting for epoxy.


The long awaited head gasket arrived:

[Jarno]

Measuring the volumes..


Only way I could think of, to really accurately measure the piston dome volume:


Anyway, my estimate had been 12,2-12,8:1 compression. Turns out I was wrong, calculator says 13,06:1 which is way too much, something has to be done. I want to be able to use pump gas which means 95E10 (10% ethanol) or 98E (5% ethanol in it), where I live. RE85 (85/15 ethanol/gasoline) is available here and there but not in every gas station.

[Jarno]

I replaced the wrist pin bushes and learned that they have to be machined to size, so no assembling rods & piston to block.. In the meanwile: Replaced the crank end bearing and assembled other stuff..








I had no clutch centering tool on hand, so I used a 12mm drill and eyeball


Test fitting the new roof lining



Connectors for engine wiring harness and radiator fan:


Started work got get the car ready for paint shop before the end of the month. Began sandblasting the doors: